Extract Knife config file find/load to a reusable component

1 files changed, 156 insertions, 0 deletions

diff --git a/lib/chef/workstation_config_loader.rb b/lib/chef/workstation_config_loader.rb
new file mode 100644
index 0000000000..faf7bd0cd1
--- /dev/null
+++ b/lib/chef/workstation_config_loader.rb
@@ -0,0 +1,156 @@
+#
+# Author:: Daniel DeLeo (<dan@getchef.com>)
+# Copyright:: Copyright (c) 2014 Chef Software, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'chef/config_fetcher'
+require 'chef/config'
+
+class Chef
+
+  class WorkstationConfigLoader
+
+    # Path to a config file requested by user, (e.g., via command line option). Can be nil
+    attr_reader :explicit_config_file
+
+    def initialize(explicit_config_file)
+      @explicit_config_file = explicit_config_file
+      @config_location = nil
+    end
+
+    def no_config_found?
+      config_location.nil?
+    end
+
+    def config_location
+      @config_location ||= (explicit_config_file || locate_local_config)
+    end
+
+    def chef_config_dir
+      if @chef_config_dir.nil?
+        @chef_config_dir = false
+        full_path = working_directory.split(File::SEPARATOR)
+        (full_path.length - 1).downto(0) do |i|
+          candidate_directory = File.join(full_path[0..i] + [".chef" ])
+          if File.exist?(candidate_directory) && File.directory?(candidate_directory)
+            @chef_config_dir = candidate_directory
+            break
+          end
+        end
+      end
+      @chef_config_dir
+    end
+
+    def load
+      # Ignore it if there's no explicit_config_file and can't find one at a
+      # default path.
+      return false if config_location.nil?
+
+      if explicit_config_file && !path_exists?(config_location)
+        raise Exceptions::ConfigurationError, "Specified config file #{config_location} does not exist"
+      end
+
+      # Have to set Chef::Config.config_file b/c other config is derived from it.
+      Chef::Config.config_file = config_location
+      read_config(IO.read(config_location), config_location)
+    end
+
+    # (Private API, public for test purposes)
+    def env
+      ENV
+    end
+
+    # (Private API, public for test purposes)
+    def path_exists?(path)
+      Pathname.new(path).expand_path.exist?
+    end
+
+    private
+
+    def locate_local_config
+      candidate_configs = []
+
+      # Look for $KNIFE_HOME/knife.rb (allow multiple knives config on same machine)
+      if env['KNIFE_HOME']
+        candidate_configs << File.join(env['KNIFE_HOME'], 'knife.rb')
+      end
+      # Look for $PWD/knife.rb
+      if Dir.pwd
+        candidate_configs << File.join(Dir.pwd, 'knife.rb')
+      end
+      # Look for $UPWARD/.chef/knife.rb
+      if chef_config_dir
+        candidate_configs << File.join(chef_config_dir, 'knife.rb')
+      end
+      # Look for $HOME/.chef/knife.rb
+      if env['HOME']
+        candidate_configs << File.join(env['HOME'], '.chef', 'knife.rb')
+      end
+
+      candidate_configs.find do | candidate_config |
+        path_exists?(candidate_config)
+      end
+    end
+
+    def working_directory
+      a = if Chef::Platform.windows?
+            env['CD']
+          else
+            env['PWD']
+          end || Dir.pwd
+
+      a
+    end
+
+    def read_config(config_content, config_file_path)
+      Chef::Config.from_string(config_content, config_file_path)
+    rescue SignalException
+      raise
+    rescue SyntaxError => e
+      message = ""
+      message << "You have invalid ruby syntax in your config file #{config_file_path}\n\n"
+      message << "#{e.class.name}: #{e.message}\n"
+      if file_line = e.message[/#{Regexp.escape(config_file_path)}:[\d]+/]
+        line = file_line[/:([\d]+)$/, 1].to_i
+        message << highlight_config_error(config_file_path, line)
+      end
+      raise Exceptions::ConfigurationError, message
+    rescue Exception => e
+      message = "You have an error in your config file #{config_file_path}\n\n"
+      message << "#{e.class.name}: #{e.message}\n"
+      filtered_trace = e.backtrace.grep(/#{Regexp.escape(config_file_path)}/)
+      filtered_trace.each {|bt_line| message << "  " << bt_line << "\n" }
+      if !filtered_trace.empty?
+        line_nr = filtered_trace.first[/#{Regexp.escape(config_file_path)}:([\d]+)/, 1]
+        message << highlight_config_error(config_file_path, line_nr.to_i)
+      end
+      raise Exceptions::ConfigurationError, message
+    end
+
+
+    def highlight_config_error(file, line)
+      config_file_lines = []
+      IO.readlines(file).each_with_index {|l, i| config_file_lines << "#{(i + 1).to_s.rjust(3)}: #{l.chomp}"}
+      if line == 1
+        lines = config_file_lines[0..3]
+      else
+        lines = config_file_lines[Range.new(line - 2, line)]
+      end
+      "Relevant file content:\n" + lines.join("\n") + "\n"
+    end
+
+  end
+end